2‐(1‐Benzotriazolyl)pyridine: A Robust Bidentate Ligand for the Palladium‐Catalyzed CC (Suzuki, Heck, Fujiwara–Moritani, Sonogashira), CN and CS Coupling Reactions

Abstract

A new class of bidentate ligand, 1-(pyridine-2-yl)-1H-benzo [d]A C H T U N G T R E N N U N G [1,2,3]triazole has been designed and employed for the palladium-catalyzed C À C (Suzuki, Heck, Fujiwara-Moritani, and Sonogashira), C À N and C À S coupling reactions. The ligand was found to be inexpensive, thermally stable, easy to synthesize from easily accessible starting materials on a multigram scale, show simplicity in use, and robustness in application, making this ligand effective for different coupling reactions. Suitably, the donor ability of the N=N bond of the benzotriazole ring and lone pair of electrons on the N of the pyridine ring enhance the bidentate ability of the ligand.

Sustainable Approach to Waste-Minimized Sonogashira Cross-Coupling Reaction Based on Recoverable/Reusable Heterogeneous Catalytic/Base System and Acetonitrile Azeotrope

“…One of the main issues related to classic cross-coupling protocols concerns the use of harmful dipolar aprotic solvents such as NMP and DMF. − This class of solvents nowadays is under strict regulation because of their toxicity and environmental impact. Their impact in terms of waste production is even higher if we consider that they are often used as aqueous mixtures. , In addition, even when a solid catalyst is used in coupling reactions, amide dipolar aprotic solvents strongly bind to catalytically active metal catalysts, such as palladium, facilitating their dissolution with a consequent significant leaching into the product.…”

Cross‐Coupling Arylations: Precedents and Rapid HistoricalReview of the Field

“…Until 1990, triphenylphosphane was used as the ligand of choice; however, a number of other contenders have appeared in the literature, the most notable being the N-heterocyclic carbenes (NHCs), but besides these well-studied ligands, others such as imines, ureas, thioureas, and selenides have been used [49]. Until 1990, triphenylphosphane was used as the ligand of choice; however, a number of other contenders have appeared in the literature, the most notable being the N-heterocyclic carbenes (NHCs), but besides these well-studied ligands, others such as imines, ureas, thioureas, and selenides have been used [49].…”

“…Of note are the benzotriazole ligands developed by Verma et al [49]. Of note are the benzotriazole ligands developed by Verma et al [49].…”

The Disappearing Director: The Case of Directed N‐Arylation via a Removable Hydroxyl Group

“…[12] Benzotriazoles are important in organic synthesis, [13] including as ligands in cross-coupling reactions. [14] …”